It’s rumored that the next-gen iPhone will adopt a higher-cost stacked logic board design to support longer battery life.

According to KGI Securities analyst Ming-Chi Kuo, the stacked logic board, also known as a “substrate-like PCB mainboard,” will result in the “iPhone 8” with an OLED display having similar dimensions to a 4.7-inch iPhone, yet comparable battery life to a 5.5-inch iPhone. Kuo stated that he expects the device to have around a 2,700 mAh L-shaped two-cell battery pack.

While battery material technology isn’t expected to see any revolutionary breakthroughs in the next three to five years, it’s thought that the mainboard can be reduced via stacking, allowing for a larger battery and extended usage time.

A stacked SLP could deliver an OLED-equipped iPhone with similar dimensions to a 4.7″ TFT-LCD iPhone with a comparable battery capacity around 2,700 mAH with an L-shaped 2-cell battery pack. The battery life of the OLED iPhone could be better than that of the 5.5” TFT-LCD model as OLED panels are more energy-efficient than their TFT-LCD counterparts.

At present, the iPhone 7 has a 1,960 mAh battery and the iPhone 7 Plus has a 2,900 mAh battery.